1. Field of the Invention
This invention pertains to siphon pumps for evacuating liquids and is particularly useful for removing hot fats from frying machines.
2. Description of the Prior Art
Frying liquids, usually vegetable shortening, must be changed periodically. In order to save time, the shortening or fat is generally changed while it is still hot and of relatively low viscosity. Changes can most safely be done by using a siphon pump to drain the tank. One commonly used device for removing the hot fat is a siphon pump of a type which has an elongated pump cylinder joined at an upper end by an upper tube which fits into the tank of fat and a lower tube which discharges downwardly into some form of filtering or collecting mechanism. To initiate a siphon effect, a piston is raised in the pump cylinder and then pushed downwardly beyond the lower tube so that a suction is created on the upper tube. Once the piston passes the lower tube, the suction created by the piston is broken but the flow of fat up through the upper tube continues from the siphon effect. This well known siphon pump, however, is expensive to manufacture and difficult to operate as the fat can congeal around the piston making initial stroking of the piston difficult.